According to the related art, in the case that a bone cement should be injected into the bone due to a disease such as a vertebral compression fracture and a tumor formed in a vertebra, etc., a bone cement insertion operation is used.
Such a bone cement insertion operation is made through a device and operation process as follows.
First, a device including an outer needle tube and an inner needle rod with a sharp one end portion are partially inserted into the bone into which the bone cement is to be injected. Next, after separating the inner needle rod from the outer needle tube, the bone cement is supplied through the outer needle tube and the bone cement is again injected into the bone while pushing the inner needle rod into the outer needle tube at constant pressure.
However, if the bone cement is leaked into a blood vessel and spinal canal, complications such as paraplegia due to pulmonary embolism and spinal nerve damage may occur. Especially in the process of continuously observing using a radiation fluoroscope when injecting the bone cement, injection should be immediately stopped if there is a doctor's opinion of the bone cement leakage. At this time, the bone cement remaining in the outer needle tube also should not be injected. If the remaining bone cement is injected, the risk of complications such as pulmonary embolism and spinal nerve damage increases. At this time, if the outer needle tube is removed after the bone cement has hardened, the bone cement in the vertebra and the bone cement in the outer needle tube becomes one body, so the risk that the bone cement will remain in the muscle and skin tissue, which is an injection path, is high. Due to this, an operation for removing the bone cement should be performed, so the patient will have considerable physical and mental pain.
Also, bone cement has a considerably high hardening speed (hardens in about seven to ten minutes) and a high viscosity. Not only that, due to the friction with a narrow wall of the injection tube, it is sometimes difficult to complete the bone cement injection within the hardening time. Especially when bone cement hardens, it hardens as one body with the injection tube, so there is a problem that the bone cement that was already filled in the bone and the injection tube become one body to make it not easy to draw the tube out.